Pharmaceutical Powders for External Use

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Questions and Answers

What is the main purpose of dusting powders for external use?

To act as a lubricant for the skin

To treat fungal infections only

To provide a cooling effect on the skin

To soothe the skin and treat various conditions (correct)

Which method is recommended for mixing constituents in preparing powders for external use?

Manual blending

Rotary mixing

Doubling up method (correct)

High-speed mixing

What is the maximum shelf life for extemporaneously prepared powders for external use?

3 months

4 weeks (correct)

6 months

2 weeks

Which sterilization method is appropriate for powders that may be applied to large areas of open skin?

Dry heat sterilization Signup and view all the answers

Which substance is commonly added to dusting powders to absorb moisture?

Zinc oxide Signup and view all the answers

What type of container is often used for packing powders for external use?

Glass, metal, or plastic containers Signup and view all the answers

Which of the following statements is true regarding insufflations?

They are less convenient to apply than other topical preparations. Signup and view all the answers

What is a necessary label indication for powders intended for external use?

For external use only Signup and view all the answers

What advantage do powdered forms of potent drugs like sodium cromoglycate offer?

They are rapidly absorbed from the lung. Signup and view all the answers

What is a characteristic feature of granules as compared to powders?

Granules are agglomerated to form larger particles. Signup and view all the answers

Which of the following statements is true about bulk powders?

They can be directly dispensed to patients. Signup and view all the answers

What is indicated by the mention of a sieve size of 180 µm?

It helps in obtaining finely divided powders. Signup and view all the answers

How does the manufacturing method of tablets differ from powders?

Tablets must be compressed to form a solid dose. Signup and view all the answers

What distinguishes tablets intended for systemic drug delivery?

The drug must be released from the tablet for effectiveness. Signup and view all the answers

What type of public awareness is indicated for powders intended for external use?

They must include 'for external use only' on labels. Signup and view all the answers

What was the innovation introduced by William Brockedon in 1843 regarding tablets?

The compression of powders to form compacts. Signup and view all the answers

Study Notes

Powders for External Use

Powders for external use are commonly used on skin, they can contain medicaments or be simple dusting powders.
Finely divided powders are typically produced using a sieve with a size of 180 µm.
Mixing ingredients for external powders is done using the "doubling up" method.
External powders should be sterilized if they are to be used on large areas of open skin or wounds.
Talc, kaolin, and other natural minerals used in powders can be contaminated with bacteria like Clostridium tetani and C. Perfringens.
To prevent contamination, ingredients should be sterilized using dry heat or the final product should be sterilized.
External use powders should not be used on areas with significant exudates as it can lead to hard crust formation.
Powders for external use should be stored in cool, dry places and labeled as "for external use only."
Examples of official external use powders include zinc oxide dusting powder compound BP, chlorhexidine dusting powder BP, and talc dusting powders BP.
Proprietary examples of external use powders include antifungal and antibacterial powders.

Insufflations

Insufflations are medicated powders blown into body cavities like ears, nose, and throat using an insufflator.
Traditional insufflations have declined in use due to their inconvenience and inelegance compared to other topical preparations.
Ensuring accurate dosing with traditional insufflators for systemically active drugs was difficult.
Modern insufflations can deliver potent drugs like sodium cromoglycate directly to the lungs for rapid absorption.

Tablets

In 1843, William Brockedon patented a machine for compressing powders into tablets.
A tablet is a solid preparation containing a single dose of one or more active ingredients, formed by compressing uniform particles.
Tablets are mainly used for systemic drug delivery but can also have local effects.
For systemic use, the drug must be released from the tablet, depending on the formulation, this can occur via chewing, dissolving, or other mechanisms.
Tablets are classified by their intended route of administration: swallowing whole, chewing, dissolving in water, or retention in the mouth.
Tablets require a variety of excipients, depending on the type of tablet and the desired properties.
For systemic use, tablet formulations aim to achieve a controlled release of the active drug over a defined period.
Tablets are typically packaged in blister packs, bottles, or tubes for protection and to ensure dosage accuracy.

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Description

This quiz covers the essential aspects of powders used for external application, including their composition, preparation methods, and safety precautions. It also discusses common ingredients and the importance of sterilization to prevent contamination. Test your knowledge on this critical area of pharmaceutical practices.